DK174046B1 - Water-dilutive, air-drying coating and its use - Google Patents

Description

in DK 174046 B1

The present invention relates to water-dilutable, air-drying coatings based on combinations of water-dilutable alkyd resins and aqueous polymer dispersions and maleized oils or fatty acids, and the use of such coatings. The products may, after incorporation of pigments, fillers and / or for the purpose in question, correspond to lacquer aids or lacquers, as coatings for wood and metal substrates, in particular for coatings and wood lacquers.

The replacement of organic solvents with water in air-drying colors and varnishes has long been an important point in the industry and their development departments. In spite of the large number of protection rights in this area, so far only a few-to-15 products have been offered.

It has now been found that, by a combination of specific water-dilute alkyd resins with polymer dispersions and maleic oils, water-dilutable, air-drying coatings can be obtained which meet significantly the consumer's diverse requirements than the products hitherto on the market.

Thus, the present invention relates to partial or complete neutralization of the carboxyl groups with bases, water-dilutive, air-drying coating compositions comprising 25 (A) 4 to 95% by weight based on the total weight of (A), (B) and (C). preferably at least 30% by weight, water-dilutable alkyd resin having a content of 30 to 70% of oxidatively drying fatty acids and whose free carboxyl groups corresponding to an acid number of 25 to 70, 30 mg KOH / g, for at least 80% they originate from methacrylic acid units which, together with other vinyl and / or (meth) acrylic monomers, are seeded on at least a portion of the fatty acids, 4 to 95% by weight, based on the total weight of (A), (B) and (C), preferably at least 20% by weight, aqueous poly. mercury dispersion based on (meth) acrylic acid ester and / or butadiene and / or styrene copolymers, and / -5 or an aqueous polyurethane dispersion, (C) 1 to 30% by weight based on the total weight of (A), (B ) and (C), preferably 5 to 20% by weight, adduct between maleic anhydride and drying oil and / or unsaturated fatty acids which build up such an oil, and / or synthetically prepared esters of these fatty acids with di or polyols, the anhydride structure thereof are opened by means of water and / or monoalcohols of 1 to 10 carbon atoms and having an acid number between 40 and 280 mg KOH / g, and 15 (D) optionally pigments, fillers and / or for the applicable use. corresponding lacquer aids and / or additives.

The coating compositions of the invention are easy to process and provide excellent, high-elasticity films with excellent resilience and excellent weather resistance. As will be apparent from the following comparative examples, comparative coating agent V (a), i.e. a coating agent without the addition of component C, not the intended improvement in the form of a better ironability, extended connection time and increased weather resistance as is the case with the coating agents according to the invention. The same applies to the comparative coating agent V (c), which also does not contain component c, and which is pigment-free formulated as wood enamel. The resulting wood lacquers exhibit good penetration and protective effect. The content of organic auxiliary solvents can be lowered to less than 5% by weight of the volatile lacquer fraction.

3 DK 174046 B1

As component (A) of the combination of the invention, alkyd resins such as those described in EP 0.295,403 A2 are used.

These alkyd resins have a free acid group content corresponding to an acid number of 25 to 70 mg KOH / g, these acid groups for at least 80% being derived from methacrylic acid units, which together with other vinyl and / or (meth) acrylic monomers in a particular reaction step have been seeded on a portion of the unsaturated fatty acids used.

The content of drying and / or semi-drying fatty acids is between 30 and 70% by weight. Of these fatty acids, a proportion of 10 to 40% by weight, based on the resin weight, is introduced in the form of fatty acid methacrylic acid copolymer.

Further, the alkyd resins contain 10 to 25% by weight polyalcohols with 2 to 6 hydroxyl groups, 10 to 20% by weight aromatic and / or aliphatic dicarboxylic acids, 0 to 15% by weight cyclic and / or polycyclic monocarboxylic acids and 0 to 5% by weight polyethylene glycol . The final products exhibit an intrinsic viscosity of between 7 and 16 ml / g measured in chloroform at 20 ° C.

For the preparation of grafted fatty acids, unsaturated fatty acids having an iodine number above 135 (preferably 160-200) and with predominantly isolated placement of the double bonds are used. Suitable are linseed fatty acid, safflor fatty acid, as well as the fatty acids of hemp oil, allelantia oil, perilla oil and scaffold oil, optionally in admixture with up to 25% by weight of dehydrated castor oil fatty acid or a comparable conjuan fatty acid produced by isomerization.

The fatty acid graft copolymers are composed of 30% to 50% by weight of the above fatty acids, 10 to 25% by weight of methacryo-ΙΟ acid and 30 to 55% by weight of other monomers which, in addition to the cC double bond, do not carry additional functional groups, the sum of the percentages must amount to 100. As DK 174046 B1 4 monomers which can be used in addition to methacrylic acid, (meth) acrylic and vinyl compounds are preferably provided that they comprise at least 80% by weight of those which form gasoline-soluble homopolymers.

Suitable include esters of methacrylic acid and acrylic acid with n-b-butanol, isobutanol, t-butanol or 2-ethylhexanol. Vinyl toluene is used to adjust the optimum film hardness of the copolymer. In smaller proportions (up to 20% by weight), monomers which form gasoline-soluble polymers such as methyl methacrylate or styrene may also be used. The graft copolymerization is carried out such that the major amount of fatty acid, optionally in the presence of minor proportions of an inert solvent, is heated to 110-150 ° C and the mixture of monomers with a suitable initiator and the remaining amount of fatty acid is added over a few hours. The reaction mixture is then kept at the reaction temperature until a residual determination shows a polymerization turnover greater than 95%. Initiators include di-t-butyl peroxide, t-butyl perbenzoate and cumol hydroperoxide.

The fatty acid methacrylic acid graft copolymers thus prepared are processed together with additional fatty acids for water-soluble alkyd resins. As fatty acids, vegetable and animal fatty acids having an iodine number greater than 120 may be used in this step, preferably a portion of the double bonds must be in the conjugated position. Suitable are, among others, soy fatty acid, linseed fatty acid, safflower fatty acid, tall oil fatty acid and castor fatty acid (German: Rizinen fatty acid).

As polyols and dicarboxylic acids, the preparation of the alkyd resins takes into account all products which are also used for the production of conventional alkyd resins. Preferably, trimethylolethane, trimethylolpropane, pentaerythritol and sorbitol are used as polyols and ortho- or iso-phthalic acid as well as adipic acid as dicarboxylic acids. Cyclic or polycyclic inonocarboxylic acids such as resin acids or benzoic acids may also be used to control film hardness. If applicable, proportions of up to 5% by weight of polyethylene glycols having a molecular weight of 1000 to 3000 can also be incorporated.

5 The esterification can be carried out by joint heating of all the components. However, using high-melting raw materials such as pentaerythritol and isophthalic acid, it is advisable to first esterify fatty acids, polyols and dicarboxylic acids alone, to obtain a clear melt and only then to add the fatty acid methacrylic acid copolymer. The esterification is then operated to such an extent that the final value of the acid number corresponds to approx. 90% of the concentration of the carboxylic groups of methacrylic acid. Since these acid groups exhibit a tertiary position in the copolymer chains and are thus sterically hindered, it can be assumed that they are esterified significantly slower than the other carboxyl groups and upon completion of the reaction they provide the major proportion of the free acid groups which effect the water solubility of the resin.

As organic water-compatible co-solvents, 20 are especially suitable for the methyl, ethyl and butyl ethers of ethylene glycol, diethylene glycol, 1,2-propylene glycol and dipropylene glycol. Of course, only limited water-compatible solvents such as n-butanol and isobutanol can also be used. The total content of organic solvents in the finished varnish should be kept as low as possible.

For the neutralization of the acid groups, besides the preferred ammonia, triethylamine, dimethyl-ethanolamine, KOH, NaOH and LiOH are suitable.

The alkyd resins can be used either in neutralized or non-neutralized form in a solution in water compatible solvents. Preferably, however, products in the form of aqueous emulsions are used, since the content of organic solvents can be substantially reduced.

6 DK 174046 B1

The component (A) is used based on the sum of binders, ie. components (A) to (C), in an amount of 4 to 95% by weight. Preferably, the combination (A) to (C) contains at least 30% by weight of this component.

As component (B), aqueous polymeric dispersions are used based on (meth) acrylic acid ester and / or butadiene and / or styrene copolymers and also polyurethane dispersions. Products of this kind are available commercially under various trade names. (Examples should be mentioned here: 10 MOWILITH VSW 6866, MOWILITH DM 772 (acrylate copolymer dispersions from HOECHST AG), NEOCRYL XK 62 (styrene-acrylate copolymer dispersion from POLYVINYL CHEMIE), ACRONAL 603 (acrylate dispersion from BAS) , LITEX CA (styrene-butadiene copolymer dispersion from Chemische Werke Huls AG), DAOTAN VTW 1210 (po ~ 15 lyurethane dispersion from HOECHST AG)). All the mentioned product names are registered trademarks of the manufacturer.

The component (B) is used based on the sum of binders, ie. components (A) to (C) in an amount of from 4 to 95% by weight. Preferably, the combination contains at least 20% by weight of this component.

The component (C), which is based on the sum of binder, is used in an amount of 1 to 30% by weight, preferably from 5 to 20% by weight, is an adduct of maleic anhydride with a drying oil or with unsaturated fatty acids which forms a such oils, and / or with hydroxyl-free synthetic esters of these fatty acids, red di- or polyols. The anhydride structure is opened prior to neutralization by reaction with water and / or monoalcohols of 1 to 10 carbon atoms. The raw materials for these adducts as well as methods for making them are known from the literature. The proportion of maleic anhydride in the adducts suitable for the present invention is between 5 and 30 wt%, preferably between 7.5 and 25 wt%, based on the adduct.

7 DK 174046 B1

As component (D), the coating agents may contain the usual pigments and fillers as well as lacquer aids or lactate additives. The choice and quantity of these components is based on the purpose of use of the coating agent.

Components (A) and (C) are preferably mixed after neutralization of the carboxylic acid groups. The addition of component (B) occurs subsequently, possibly after addition of a portion of the diluted water.

The reprocessing of the binder combination with the component of component (D) takes place in a known manner and needs no further explanation. The same also applies to the processing of the coating composition according to the invention.

The following examples illustrate the invention without limiting its scope. All entries in parts or percentages are calculated as units of weight unless otherwise indicated.

Preparation of component (h)

Preparation of fatty acid copolymer A 1: 30 parts linseed fatty acid and 5 parts xylene is heated to 135 to 20 140 ° C. At this temperature, at a steady rate, for a period of 6 to 8 hours, a mixture of 32 parts of isobutyl methacrylate, 6 parts of vinyltoluene and 21 parts of methacrylic acid, and a mixture of an additional 11 parts of linseed fatty acid, 3 parts of t-butyl perbenzoate, 1 part of dibenzoylperoxide ( 50%) and 5 parts of xylene. After the addition is complete, the reaction temperature is maintained until a residual determination shows at least 95% polymerization reaction. If the reaction proceeds too slowly, a portion of t-butyl perbenzoate is added to the portion. The copolymer has an acid number of 209 mg KOH / g and a 30 viscosity (dimethylformamide, 20 ° C) of 5.5 ml / g.

8 DK 174046 B1

Preparation of Alkyd Resin In a suitable reaction vessel, 200 parts of safflor fatty acid, 110 parts of isomerized linoleic acid (about 50% 9,11-linoleic acid), 115 parts of pentaerythritol and 100 parts of isophthalic acid 5 are stored for as long as needed. because a clear melt has occurred. After another 1 hour, 340 g of fatty acid copolymer Al is added and reacted at 200 ° C until the indicated final values are reached. After extracting the inactive solvent (from the copolymer), adjust the portion with ethylene glycol monobutyl ether to a solids content of 87% and emulsify at 50 ° C with a dilute aqueous ammonia solution. The amount of ammonia and the amount of water are chosen such that an emulsion having a pH of 8.2 to 8.4 and a solids content of 40% is obtained. The resin solution is a milky to transparent liquid with a pronounced structural viscosity.

(XI) As component (B), the following conventional polymer dispersions are used! (The statements were taken from technical mark sheets).

20 (B1) Finely divided, medium viscous copolymer dispersion of α-acrylic esters, 46% in water, minimum film formation temperature approx. 40 ° C (DIN 53787); trade name SYNTHACRYL VSW 6866 (HOECHST AG).

(B2) Fine dispersion, medium viscous copolymer dispersion of 25 acrylic acid esters, 46% in water, minimum film formation temperature approx. 14 ° C (DIN 53787); Trade Name: MOWI-LITH D 772 (HOECHST AG).

(B3). Low viscous, fine-dispersed aqueous copolymer dispersion of acrylic and methacrylic acid esters, 50% in water, at least 30 film formation temperature approx. 16 ° C (DIN 53787); he part name: ACRONAL 603 (BASF AG).

9 DK 174046 B1 (B4) Anionic acrylic styrene copolymer dispersion, 42% in water, minimum film formation temperature approx. 30 ° C (DIN 53787); Trade Name: NEOCRYL XK 62 (POLYVINYL CHE-MIE).

(B5) Aqueous, emulsifier-free polyurethane dispersion, 40% in water; Trade Name: DAOTAN VTW 1210 (HOECHST AG).

(II) Preparation of component (C)

Component (Cl): In a suitable reaction vessel, 700 parts of soybean oil and 100 parts of malic anhydride 10 are reacted at 200 to 210 ° C under inert gas until free maleic anhydride can no longer be detected. After cooling to 110 ° C, 162 parts of diethylene glycol monobutyl ether and 3 parts of triethylamine are added and the reaction is carried out until an acid number of approx. 55 mg KOH / g. The product is diluted with methoxypropoxypropanol to a solids content of 90%.

Component (C2): In the same manner as described for (C1), an adduct of 280 parts of linseed fatty acid and 100 parts of maleic anhydride is prepared, whose anhydride groups are opened at 80 ° C with 35 parts of methanol in the presence of 3 parts of triethylamine. The product 20 exhibits an acid number of approx. 240 mg KOH / g and diluted with methoxypropoxypropanol to a solids content of 90%.

Component (C3): A mixture of 150 parts dehydrated castor oil and 150 parts linseed oil is stirred under inert gas for 1 hour at 250 ° C and then reacted at 200 ° C with 100 parts maleic anhydride. The anhydride groups are opened at approx. 100 ° C with 162 parts diethylene glycol monobutyl ether in the presence of 2 parts triethylamine. The reaction product (acid number about 90 mg KOH / g) is diluted to a solids content of 90% with methoxypropoxypropanol.

Examples 1 - 3 and Comparative Example V (a) Water-resilient applicator lacquer. white 10 DK 174046 B1 On a agitator ball mill, pigment tear mixtures with component (A) having the following composition are prepared:

Example 1: 83 parts

Example 2: 115 parts component (A), 40% Example 3: 177.5 parts 1.5 parts ammonia solution 25% 100 parts titanium dioxide (Rutile) 1 part combination dryer, water-diluted (Co, Ba, Zr) 2 parts anti-skin forming agent (oxime base) 1 part foaming agent (silicone-free) 30 parts water 15 The pigment-binder ratio of these pigment pastes is 3: 1, 2: 1 and 1: 0.7, respectively.

For Examples 1 to 3, the pigment tear mixtures are supplemented with components (B) and (C) as well as additional additives similar to those given in Table 1. Comparative Example V (a) contains no component (C).

Table 1

Example_1_2_3_V (a ^ pigment paste of component 25 (A). See above_218.5 250.5 313.0 218.5 slip and discharge agent 3333 foam, silicone-free 1111 dispersion (B1), 46% 127 95.7 - 145 _ (B2) _ - _-- -43 ammonia solution, 25% 1 1 1 - adduct (Cl), 90% 10 (C2), 90% - - 10 (C3), 90% - 10% lacquer solids content 56% 56% 56 % 56% pigment binder 1: 1 1: 1 1: 1 1: 1 ratio 5 After setting the pH value with ammonia solution to 8.8 - 9.1, the varnishes are applied to sanded boards of soft wood.

The test results are summarized in Table 2.

As a further comparative example (V (b)), a commercially available wood dispersion dye is used on the basis of 10 dispersion (B1).

The tests were carried out as follows: 1. Ironability: The workability of the materials was assessed subjectively according to a points system (rating l = very good, 5 = very poor).

15 2. Connection time: A wooden board was sprinkled on the half side with the sample lacquer. After every 5 minutes, the edge zone irreversibility was tested by streaky application of varnish.

At the specified time, "connection" can no longer be made.

3. Drying; Drying Recorder at 20 ° C and a coating thickness of 150 μιη wet film on glass plates.

4. Paintability: Iron a wooden board with the sample paint.

After every 2 hours, the paintability was tested by streaky application of varnish. After the specified time, an impeccable paintability is obtained.

5. Storage stability of the varnish: All varnishes were, after adjustment of the pH value, immutable after a storage period of 4 weeks at 50 ° C.

12 DK 174046 B1 6. Exposure of lacquers or lasers to the free weather ·:

All lacquers or lasers containing component C are in good order after being exposed to the free weather for 12 months (spruce boards, 45 ° to the south) with respect to 5 yellowing, dirt uptake, scratching and graying.

in

Table 2

Example_1 2_3 Vfa) V (b) Strength Durability_1-2 l_l 3-4_3-4 10 Connection Time (Min. 40 40 55 10_2 Drying (25 ° C) Adhesive (Min. 90 90 90 90 60 Grab Resistant) _3.5 4_4_2_J> _1.5 overcoatability ftimer) _14 13 14_8_12 15 weatherproofing scratch formation_ 1 1_1_3_3-4 qlans assessment_1-2 1-2 1-2 3_4 blistering_l_l_1_3_3-4 whitening 2 0 fslr formation ^ _1-2 1-2 1-2_2-3_3

EXAMPLES 4 TO 8 AND COMPARATIVE EXAMPLE Vfc ^ water-recoverable wood lacquers In accordance with the following formulations, water-dilutable wood lacquers were prepared (Table 3).

13 DK 174046 B1

Table 3

Example_4_5_6_7_§_Vf c) Component (A), 40% 246.0 267.0 205.0 222.0 222.5 370.0 Component (Cl), 90% 40.0 - 40.0 - 20.0 _ (C3). 90% - 20.0 - 20.0 - Ammonia Copying 25% 4.0 Siquative Mixture 4.0 Fungicide Solution 0.5 10 Matting Agent (2) 32.5 KW Solvent (3) 7.0 Mixture DEME (4) 7, 0 anti-caking agent (1) 2.0 15 anti-scrubbing agent (5) 2.0 scrubbing agent (l) 2.0 leaching agent 4.0% ammonia solution, 25% 3.0 3.0 3.0 3.0 3.0 3.0 water_170. 0 135.0 202.0 170.0 164.0 225.0 20 component (B1) - 117.0 - - - (B2) - - 97 (B3) 89 ~ - - - 60.0 (B4) - - - 128 _fB51 134 (1) See Examples 1-3 (2) Ethylene Wax / Surface Silica (3) Lacquer Gas (Boiling Point 184 - 207eC) (4) Diethylene Glycol Monoethyl Ether (5) Modified Castor Oil 30 The lasers exhibit a solids content of about 35 After adjusting the pH of 9.2 and an expiry time of 30 to 35 seconds (DIN 53211/20 ° C), the lasers are applied by ironing on spruce boards. Comparative Example V (c) was formulated without adduct ratio (component C). Comparative Product (e.g. Sample V (d)) was tested a conventional water dilutable wood lacquer.

The tests were conducted in the same way as in Examples 1 to 3. The results are summarized in Table 4.

Table 4 5 _________________

Example_4 5 6_7_8 Vfc ^ Vfd ^ Ironability ............ 1_111 _ 1-2 _2-3 2-3 Drying (25 ° C) Adhesive (Hours) 3 332211 10 Scratch Resistant (Hours) _4_4_i_3. 5 3_1.5_ Irritability (After Hours! _3.5 3.5 5 5 3.5 3 6 Road Testing Scratching 1 111 1-2 2 3-4 15 Blistering 1 111 1-2 2-3 2-3 Cretaceous 2 1-2 1-2 1-2 1-2 2-3 3

Claims (4)

Water-dilutable, air-drying coating composition, characterized in that it consists of 5 (A) 4 to 95% by weight, based on the total weight of (A), (B) and (C), preferably at least 30% by weight, of water. Thin alkyd resin having a content of 30 to 70% oxidative drying fatty acids, and whose free carboxyl groups corresponding to an acid number of 25 to 70 10 mg KOH / g, for at least 80% originating from methacrylic acid units which together with other vinyl and / or (meth) acrylic monomers are seeded on at least a portion of the fatty acids, (B) 4 to 95% by weight based on the total weight of (A), 15 (B) and (C). ), preferably at least 20% by weight, aqueous polymer dispersion based on (meth) acrylic acid ester and / or butadiene and / or styrene copolymers, and / or an aqueous polyurethane dispersion, (C) .1 to 30% by weight, calculated on the total weight of (A), 20 (B) and (C), preferably 5 to 20% by weight, adduct of maleic anhydride with drying oil and / or with unsaturated fatty acids which builds up such an oil, and / or with synthetically prepared esters of these fatty acids with di- or polyols, the anhydride structure 25 thereof being absorbed red water and / or monoalcohol having 1 to 10 carbon atoms, and the acid number thereof being between 40 and 280 mg KOH / g, and (D) optionally pigments, fillers and / or for the particular application corresponding to leaching aids 30 and / or additives. Water-dilutable coating agent according to claim 1, characterized in that the maleic anhydride adducts used as component (C) have a content of maleic anhydride of 5 to 30% by weight, preferably 7.5 to 25% by weight. Use of a coating agent according to claim 1 or 2 as a coating varnish or wood enamel. Use of the coating agent according to claim 1 or 2 as solvent-poor varnishes, the amount of organic solvent in the volatile proportion being less than 5% by weight.